Is a great leader someone who can get everyone to follow him, and is the measure of a leader the results booked... or the backing of the people?

It's clear that that no leader will be liked by everyone, but the better leader and the greater they can make the cause the more they can get people behind them. Think of Churchill, Mandela or Ghandi, they were all able to unify in part due to their leadership but also in part to the cause they stood for or created.A similar situation could be seen by Castro or Hitler...great leaders as well? Obviously not according to all people, but they were able to create cause so powerful that they were able to unite the masses, weren't they?

So the key seems to be creating a cause powerful enough to unite everyone behind...

What are your thoughts on this?